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Calculate the coordinateUncertaintyInMeters

Source: R/dwc_coordinateUncertaintyInMeters.R
dwc_coordinateUncertaintyInMeters.Rd

This function calculates the uncertainty in meters associated with a given set of geographic coordinates. The uncertainty is the sum of two parts:

  1. the uncertainty associated with the coordinate precision given a datum and latitude. This is calculated following the equations found at: http://georeferencing.org/georefcalculator/docs/GeorefGuide.html#imprecision_in_coordinates. If the coordinate reference system is unknown, the default value of 5,359 meters is assigned for this component. See Details.

  2. the uncertainty associated with the GPS recording device. By default this is given as 30 meters.

Usage

dwc_coordinateUncertaintyInMeters(
  decimalLatitude,
  coordinatePrecision,
  geodeticDatum,
  gps_uncertainty = 30
)

Arguments

decimalLatitude

Output of dwc_coordinates. Latitude in decimal degrees. See: http://rs.tdwg.org/dwc/terms/decimalLatitude.

coordinatePrecision

Output of dwc_coordinatePrecision. The precision of the coordinates in degrees. Value must be between 0.00001 and 1. See: http://rs.tdwg.org/dwc/terms/coordinatePrecision.

geodeticDatum

Output of dwc_coordinates. The spatial reference system associated with the coordinates given as an EPSG code as in the example: "EPSG:4326". See: http://rs.tdwg.org/dwc/terms/geodeticDatum.

gps_uncertainty

The uncertainty in meters recorded by the GPS device. Default is 30.

Value

A numeric. A value that can be used in the Darwin Core coordinateUncertaintyInMeters

field.

Details

Please see, Wieczorek C, J Wieczorek (2021) Georeferencing Calculator. Available: http://georeferencing.org/georefcalculator/gc.html for more options and further details.

The uncertainty associated with geographic coordinates from an unknown datum is taken from https://docs.gbif-uat.org/georeferencing-best-practices/1.0/en/#uncertainty-from-unknown-datum. Note that this is a worst-case scenario whilst this function lacks the ability to correctly determine the uncertainty of an unknown datum. If you have only a small number of locations and an unknown datum, we recommend using the Wieczorek C, J Wieczorek (2021) Georeferencing Calculator. The output of the calculator can be copied into R using dwc_format_gco.

Examples

dwc_coordinateUncertaintyInMeters(-41.17472, 0.01, "EPSG:4326", 30)
#> [1] 1422